No member of council, including supervisors, shall hold any other office of honor or profit in government, except military commissions and commissions as notaries public, during his elected term. After adoption of a form of government as provided for in this chapter, council shall by ordinance prescribe the salary and compensation for its members. After the initial determination of salary, council may by ordinance adjust the salary but the ordinance changing the salary is not effective until the date of commencement of terms of at least two members of council elected at the next general election following the enactment of the ordinance affecting the salary changes at which time it will become effective for all members. A chairman of a county council who is assigned additional administrative duties may receive additional compensation as the council may provide. The additional compensation becomes effective with the passage of the ordinance increasing the compensation of the chairman. Members may also be reimbursed for actual expenses incurred in the conduct of their official duties. The restriction on salary changes does not apply to supervisors under the council-supervisor form of government whose salaries may be increased during their terms of office but supervisors shall not vote on the question when it is considered by council.